How It Works

Electrochaea employs a patent-pending biological process to convert low-cost and stranded electricity into pipeline-grade renewable gas for direct injection into the existing natural gas grid. The core of our power-to-gas technology is a proprietary biocatalyst that can be deployed in a simple and cost-effective energy conversion system.

BiocatalystElectrochaea's biocatalyst is a selectively evolved - not genetically modified - strain of methanogenic archaea, a single-celled microorganism that has populated Earth for billions of years and can be found in a broad range of habitats, including some of the most extreme environments on the planet. The strain of archaea used in our power-to-gas process has been adapted for industrial application by Prof. Laurens Mets at the University of Chicago.

Our archaea exhibit several properties that are unique and have not been observed in wildtype strains, including high mass conversion efficiency, tolerance to many contaminants typically found in industrial CO2-sources (oxygen, hydrogen sulfide, particulates), high selectivity in methane production, and very fast reaction kinetics. In addition, the microbes are self-replicating and hence do not require periodic replacement.

System DesignElectrochaea is currently pursuing a two-step power-to-gas system that uses an off-the-shelf electrolyzer to produce hydrogen. This hydrogen is then fed to a separate bioreactor along with carbon dioxide from a biogenic or industrial source. The microbes are indifferent as to the source of CO2 and can use raw biogas from anaerobic digesters, fermentation off-gas from breweries and ethanol plants, and flue gas from oxycombustion processes. Because of the high selectivity of the microbes, minimal post-reaction gas treatment is needed before the product gas is injected into the gas grid. Oxygen and heat are produced as by-products from the process and can be sold in a broad range of different markets, either on-site or off-site.

Development Activities

Industrial Biogas Test (1 kW), United StatesIn October 2011, Electrochaea successfully tested many of the biocatalyst's properties using carbon dioxide from a biogas plant digesting brewery waste. The process ran continuously using unfiltered, unseparated biogas containing approximately 30% carbon dioxide and 68% methane and up to 6,000 ppm of hydrogen sulfide. The system performed stably, reliably, and no contamination problems were identified.

Foulum Project (pre-commercial), DenmarkWith a grant of $1.2 million from the Danish Energy Agency (EUDP), we tested our power-to-gas technology in a pre-commercial setting using a 10,000-liter reactor vessel and raw biogas as a carbon dioxide source. The system ran for more than 3,200 hours between January and November 2013 at Aarhus University's Biogas Research Center in Foulum, Denmark. Supported by E.ON, Energie 360° (formerly Erdgas Zürich), ewz (the City of Zurich's utility), and NEAS Energy, the project demonstrated the efficiency, productivity, robustness, and responsiveness of Electrochaea's power-to-gas technology.

BioCat Project (commercial scale), DenmarkIn February 2014, Electrochaea announced the start of its commercial scale technology demonstration project. Located at the wastewater treatment plant Avedøre in Copenhagen, Denmark, the BioCat Project's main objective is to design, engineer, construct, and test a 1-MW power-to-gas plant based on Electrochaea's biological methanation technology.

During 3,000 hours of operation, the facility will draw renewable electricity during times of low demand and convert that electricity to renewable gas for direct injection into - and storage in - a nearby gas distribution grid. Biogas produced on-site via anaerobic digestion will deliver the carbon dioxide required for methanation. Oxygen and heat, which are generated as by-products in the power-to-gas process, will be captured and utilized in the on-site wastewater operations. The facility will also provide frequency regulation services to the Danish power grid.

Electrochaea acts as the project leader and is supported by Hydrogenics, Audi, NEAS Energy, HMN Gashandel, BIOFOS, and Insero Business Services. The project is generously supported with a multi-million Euro grant from ForskEL, a technology development support program administered by the Danish power and gas transmission grid operator Energinet.dk. Anticipated to conclude by December 2015, the project will lift Electrochaea's technology to market maturity.